Molecular and histological detection of Coxiella burnetii in ruminants in East Java, Indonesia

Coxiella burnetii is an obligate intracellular bacterium that causes Q fever and belongs to the gamma subdivision of Proteobacteria. Several studies discovered incidences of Q fever in various parts of Indonesia, primarily in ruminants. Identification and detection of Q fever in East Java province was reported in 1976. Since then, there has been no report of the presence of this disease in the East Java region. This research aimed to detect the current presence of C. burnetii in ruminants in East Java using samples of the liver, spleen, kidney, lung, and heart of 125 cattle and 156 local goats slaughtered in slaughterhouses in East Java province. Detection of C. burnetii was performed by nested PCR method using outer membrane protein (OMP) and 16S rRNA primers, followed by confirmation using the immunohistochemistry method and hematoxylin-eosin staining. The results showed that C. burnetii bacteria were only detected in 8 out of 80 (10%) local goat samples from Malang by nested PCR using OMP primer. In comparison, nested PCR with 16SrRNA primer could only detect C. burnetii in 3 out of 8 goat's positive samples. Furthermore, immunohistochemistry showed immunoreactivity in the lung, spleen, and kidney. The positive sample of C. burnetii was found only in a small part of Malang local goats but neither in cattle in Malang nor other ruminants in other areas of East Java province. The results of this study strengthen the assumption that Q fever has already been endemic in East Java province.